<template>
  <!-- 轮播图组件 -->
  <div class='xtx-carousel' @mouseenter="stopFn" @mouseleave="startFn">
    <ul class="carousel-body">
      <!-- 轮播图 -->
      <li class="carousel-item" v-for="(item,i) in sliders" :key="i" :class="{fade:i===index}">
        <RouterLink v-if="item.hrefUrl" :to="item.hrefUrl">
          <img :src="item.imgUrl" alt="" />
        </RouterLink>
        <div v-else class="slider">
          <RouterLink v-for="goods in item" :key="goods.id" :to="`/product/${goods.id}`">
            <img :src="goods.picture" alt="">
            <p class="name ellipsis">{{goods.name}}</p>
            <p class="price">&yen;{{goods.price}}</p>
          </RouterLink>
        </div>
      </li>
    </ul>
    <!-- 上一张 -->
    <a href="javascript:;" class="carousel-btn prev"><i class="iconfont icon-angle-left"></i></a>
    <!-- 下一张 -->
    <a href="javascript:;" class="carousel-btn next"><i class="iconfont icon-angle-right"></i></a>
    <!-- 指示器 -->
    <div class="carousel-indicator">
      <span v-for="(item,i) in sliders" :key="i" :class="{active:index===i}" @click="toggleFn(i)"></span>
    </div>
  </div>
</template>
<script>
import { ref, watch, onUnmounted } from 'vue'
export default {
  name: 'XtxCarousel',
  props: {
    sliders: {
      type: Array,
      default: () => []
    },
    duration: {
      type: String,
      default: 1500
    },
    autoPlay: {
      type: Boolean,
      default: true
    }
  },
  setup(props) {
    // 默认显示的图片的索引
    const index = ref(0)
    let timer = null
    // 自动播放
    const autoPlayFn = () => {
      clearInterval(timer)
      timer = setInterval(() => {
        index.value++
        // 最后一张
        if (index.value >= props.sliders.length) {
          index.value = 0
        }
      }, props.duration);
    }
    // 继续循环
    const startFn = () => {
      if (props.sliders.length && props.autoPlay) {
        autoPlayFn()
      }
    }
    // 停止循环
    const stopFn = () => {
      if (timer) clearInterval(timer)
    }
    // 指示器
    const toggleFn = (step) => {
      // const newIndex = index.value + step
      // if (newIndex >= props.sliders.length) {
      //   index.value = 0
      //   return
      // }
      // if (newIndex < 0) {
      //   index.value = props.sliders.length - 1
      //   return
      // }
      index.value = step
    }
    // 监听器
    watch(() => props.sliders, (newVal) => {
      if (newVal.length && props.autoPlay) {
        index.value = 0
        autoPlayFn()
      }
    }, { immediate: true })
    // 组件销毁
    onUnmounted(() => {
      clearInterval(timer)
    })
    return { index, startFn, stopFn, toggleFn }
  }

}
</script>
<style lang="less" scoped>
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
      // 轮播商品
      .slider {
        display: flex;
        justify-content: space-around;
        padding: 0 40px;
        > a {
          width: 240px;
          text-align: center;
          img {
            padding: 20px;
            width: 230px !important;
            height: 230px !important;
          }
          .name {
            font-size: 16px;
            color: #666;
            padding: 0 40px;
          }
          .price {
            font-size: 16px;
            color: @priceColor;
            margin-top: 15px;
          }
        }
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>